Going to the Mountain (Mt. Etna is “the Mountain” for us as Sicilians or better from us from Catania) is always electrifying and exciting: the mind and the body are always grateful!
On Etna challanges and discoveries never end, year after year there are always new “puttusi” (holes in Sicilian dialect), destinations to explore. The guides of Etna Experience love Mt. Etna and its surroundings and in their free time they are used to meet to walk and explore new routes.
This time it was the turn of the “Pious Brothers” ( Frati Pii ) or “Due Pizzi” in the northern sector of Mt. Etna. It is a particularly evocative place where the two souls of the volcano meet and clash: the ancient one ( Sciara del Follone) and the recent one ( eruption 2002, eruption 1947, etc) in a contrast of colors and shapes that never bore. The black and shiny flows on one hand and the sinuous rounded shapes on the other. All in a snowy April and under the watchful and permanent guard of the North-East Crater.
In this set of elements so different to a careful eye stand out the “Frati Pii” or “Due Pizzi”: the largest hornitos of Etna (are more than 30 meters high) formed during the eruption of 1614-1624, one of the longest lateral eruptions and dedicated to the legend of the brothers Amphinome and Anapia.
The myth described in “De Aetna”, one of the myths of the Appendix Vergiliana, tells the story of two brothers who, defying the lava of the volcano, manage to save their elderly parents.
In the poem, the miserly manus of the common men is contrasted. Faced with the violence and tragedy of the eruption, they only think of saving the material goods and the pietas of the two virtuous brothers who face the danger of saving their parents’ lives.
In this way they are pardoned and the flashes of the lava flow become “diagonal” and spare the two protagonists: “brothers saved (incolumes) because they are pious”.
The concept of pietas and devotion and respect towards the gods, but also towards the homeland and the parents, which is also present in the Aeneid with the pius Aeneas, which is spared from the flames and blows of enemies while fleeing from Troy with his father Anchises on his shoulders.
Two are the morals that emerge in the pseudo Virgilian poem: the bones artes that for men must represent the real wealth and that is the observation and investigation of natural phenomena that serve to overcome all fear and superstition, and the virtue of mind that gives meaning to the same scientific investigation.
The Due Pizzi, as we said at the beginning, are two hornitos, cones of welded slag (spatter cones) that are generally found in the lower parts of the eruptive fractures and are fed by an underlying lava flow. In this specific case, the emission centres that fed them were probably located higher up and no longer visible today because they were covered by recent volcanites or more likely to be magma emission centres themselves.
The cones are part of the longest side eruption of Mt. Etna well recognizable in the landscapes of the picturesque “Sciara del Follone”. Here emerge the lava “pahoehoe”, basaltic lava more fluid and less crystalline than the most common lava “aa” Etna.
The existence of the two different lava morphologies depends on different factors such as the viscosity, the slope of the ground, the rate of emission and the rate of deformation of the lava flow, and finally the quantity and shape of the crystals inside.
In particular, on Mt. Etna, the degree of cooling imposed by the rate of volatile dissolution in the final portion of the volcano’s lead system plays an even more central role.
A slow rate of magma rise promotes degassing and nucleation, the viscosity increases and results in a morphology AA, on the contrary the lava pahoehoe are associated with a rapid rise to the surface of a magma little degassed and undercooled.
In the case of the sciara del Follone there are both morphologies and much more: mounds, mega-tumuli, terraces, lava flows, ingestions and ephemeral mouths in a set now partially covered by more recent castings that would be interesting to discover and catalog in detail.
Thanks to Silvia for sharing this experience with us!